For they shall eat, and not have enough - This is almost a proverbial saying of Holy Scripture, and, as such, has manifold applications. In the way of nature, it comes true in those, who, under God's affictive Hand in famine or siege, "eat" what they have, but have "not enough," and perish with hunger. It comes true in those, who, through bodily disease, are not nourished by their food. Yet not less true is it of those who, through their own insatiate desires, are never satisfied, but crave the more greedily, the more they have. Their sin of covetousness becomes their torment.
They shall commit whoredom and not increase - Literally, "they have committed whoredom." The time spoken of is perhaps changed, because God would not speak of their future sin, as certain. There is naturally too a long interval between this sin and its possible fruit, which may be marked by this change of time. The sin was past, the effect was to be seen hereafter. They used all means, lawful and unlawful, to increase their offspring, but they failed, even because they used forbidden means. God's curse rested upon those means. Single marriage, according to God's law, "they twain shall be one flesh," yields in a nation larger increase than polygamy. God turns illicit sexual intercourse to decay. His curse is upon it.
Because they have left off to take heed to the Lord - Literally, "to watch, observe, the Lord." The eye of the soul should be upon God, watching and waiting to know all indications of His will, all guidings of His Eye. So the Psalmist says, "As the eyes of servants look unto the hand of their masters, and as the eyes of a maiden unto the hands of her mistress, even so our eyes wait upon the Lord our God, until He have mercy upon us" Psalm 123:2. The Angels of God, great and glorious as they are, "do alway behold the Face of the Father" Matthew 18:10, at once filled with His love, and wrapped in contemplation, and reading therein His will, to do it. The lawless and hopeless ways of Israel sprang from their neglecting to watch and observe God. For as soon as man ceases to watch God, he falls, of himself, into sin. The eye which is not fixed on God, is soon astray amid the vanities and pomps and lusts of the world. So it follows;

They shall eat, and not have enough - Whatever means they may use to satisfy or gratify themselves shall be ineffectual.

For they shall eat, and not have enough: they shall (l) commit whoredom, and shall not increase: because they have left off to take heed to the LORD.
(l) Showing that their wickedness will be punished in all ways: for even though they think by the multitude of wives to have many children, yet they will be deceived of their hope.

For they shall eat, and not have enough,.... Namely, the priests; for of them the words are continued, who ate of the sacrifices of the people, and of feasts made in honour of idols; and yet, either what they ate did not satisfy or nourish them, or else their appetites were still greedy after more of the same kind: or this may respect a famine, either at the siege of Samaria, or in their captivity; when they who had lived so voluptuously should have so little to eat, that it should not satisfy them: or though, as others, they eat to the honour of their idols, expecting to be blessed with plenty by them, they shall not have it:
they shall commit whoredom, and shall not increase; that is, their offspring; they shall not beget children, so the Targum, Jarchi, and Kimchi; or the children they beget shall quickly die; yea, though they commit whoredom in the idol's temple with that view, where the women prostituted themselves for that purpose:
because they have left off to take heed to the Lord; to his word, and worship, and ordinances, which they formerly had some regard unto, but now had relinquished: or, "the Lord they have forsaken", or "left off to observe" (y); his ways, his word, and worship. R. Saadiah connects this with the following words, they have forsaken the Lord to observe fornication and wine; but wrongly.
(y) "Jehovam desierunt observare", Junius & Tremellius, Piscator, Rivetus, Liveleus; "ad observandum", Schmidt; "reliquerunt observare", Cocceius; "deseruerunt observare", so some in Vatablus.

eat, and not have enough--just retribution on those who "eat up (greedily) the sin of My people" (Hosea 4:8; Micah 6:14; Haggai 1:6).
whoredom, and . . . not increase--literally "break forth"; used of giving birth to children (Genesis 28:14, Margin; compare Genesis 38:29). Not only their wives, but their concubines, shall be barren. To be childless was considered a great calamity among the Jews.

"They will eat, and not be satisfied; they commit whoredom, and do not increase: for they have left off taking heed to Jehovah." The first clause, which still refers to the priests on account of the evident retrospect in ואכלוּ to יאכלוּ in Hosea 4:8, is taken from the threat in Leviticus 26:16. The following word hiznū, to practise whoredom (with the meaning of the kal intensified as in Leviticus 26:18, not to seduce to whoredom), refers to the whole nation, and is to be taken in its literal sense, as the antithesis לא יפרצוּ requires. Pârats, to spread out, to increase in number, as in Exodus 1:12 and Genesis 28:14. In the last clause Lשׁמר belongs to Jehovah: they have given up keeping Jehovah, i.e., giving heed to Him (cf. Zac 11:11). This applies to the priests as well as to the people. Therefore God withdraws His blessing from both, so that those who eat are not satisfied, and those who commit whoredom do not increase.

Not have enough - They shall not be nourished, nor satisfied with what they eat. Shall not increase - They shall not hereby increase the number of their children, either the women shall not bear, or the children shall not live.